3.1 Biological elements

Question 1

cations and roles (5)

Ca2+,Na+,K+,H+,NH4+

Answer 1

1. Ca2+ (nerve impulse transmission/muscle contraction)
2. Na+ (nerve impulse transmission/kidney function)
3. K+ (nerve impulse transmission/stomatal opening)
4. H+ (catalysis of reactions/pH determination)
5. NH4+ (production of nitrate ions by bacteria)

Question 2

anions and roles (5)

NO3-,HCO3-,Cl-,PO4 3-,OH-

Answer 2

1. NO3- (nitrogen supply to plants)
2. HCO3- (maintenance of blood pH)
3. Cl- (balance positive charge of sodium and potassium ions in cells)
4. PO4 3- (cell membrane, nucleic acid and ATP formation)
5. OH- (catalysis of reactions/pH determination)

Question 3

carbohydrate monomer and polymer

Answer 3

monosaccharides

polysaccharides

Question 4

proteins monomer and polymer

Answer 4

amino acids

polypeptide/proteins/enzyme

Question 5

nucleic acids monomer and polymer

Answer 5

nucleotides

DNA, RNA

Question 6

monomers —> polymers

Answer 6

condensation (making bonds)

removal of H2O molecule

Question 7

polymers —> monomers

Answer 7

hydrolysis (breaking bonds)

addition of H2O molecule